This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This Core focuses on identifying the nature of cells after marrow cell transplantation and during repair and regenerative processes. The regenerative processes involve not only skin, but also muscle and pancreatic cells. The core is capable of several analyses. Donor cells and their specific lineages are ascertained and colocalized by high resolution microscopy and immunofluroescence. Donor cells are tracked in tissue sections or cell suspensions by expression of GFP, beta-galactosidase or the presence of male DNA. The lineage of identified donor cells are ascertained by standard morphology, geographical location and immunohistochemistry. Colocalization of donor and lineage markers are confirmed using fluorescent microscopy. The core has acquired high resolutions microscopy and the ability for time lapse photography, including for GFP+ cells. A state of the art IVIS system provides project leaders and other investigators with the ability to track down cells in live animals.